Describe Environment

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description must carry behavioral disclosure. The verb 'Report' implies a read-only, non-destructive operation, and the description explains what information it surfaces (installed backends, compositor advertising, summary). However, it never explicitly states that it has no side effects, requires no special permissions, or is safe to call repeatedly. The gap is moderate given the read-only nature of the verb.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, front-loaded with the core purpose. The second sentence efficiently adds the key usage trigger. No wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter diagnostic tool with an output schema, the description supplies the essential purpose and usage context. The output schema covers return values, and no parameters require explanation. Nothing critical is missing for an agent to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is nothing for the description to add beyond the schema. Baseline for zero parameters is 4; the description appropriately avoids discussing inputs.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ('Report') and resource ('which backends this machine offers, and which were selected'). It is clearly a diagnostic/environment inspection tool, distinct from the action-oriented siblings (move_mouse, click_mouse, etc.) even though it does not name them explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives a clear trigger: 'Call this first when a capture or an input action fails.' This tells the agent when to reach for the tool. It does not provide explicit when-not-to-use conditions or name alternative diagnostic tools, so it falls short of a full 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.